The Fianna Fáil leader also said Sinn Féin is "incapable of respecting anyone outside its own ranks".

During his speech at the Wolfe Tone commemoration, Mr Martin attacked Sinn Féin saying: "How dare they claim to own Irish republicanism? No organisation which fails to expose child abusers, racketeers and murderers can call itself republican."

Mr Adams hit back, saying Mr Martin was following the example of the late British prime minister Margaret Thatcher in trying to "criminalise the republican struggle".

"However, like Thatcher, Micheál Martin will fail. Most citizens see through his cynical opportunism in relation to the peace process, which is all to do with fear about the electoral advance of Sinn Féin in the South," the Sinn Féin president said in a statement.

"Unlike Fianna Fáil, Sinn Féin has a mandate in both parts of this island and in the North we have been central to the ongoing and positive transformation of society."

At the Fine Gael presidential dinner on Saturday, Taoiseach Enda Kenny warned party members about the prospect of Sinn Féin and Fianna Fáil forming a government after the General Election.

But Martin also believes that he can form a government after the General Election without going into coalition with either Fine Gael or Sinn Féin.

Mr Martin's claim comes despite the latest opinion poll showing Fianna Fáil down a point to 19pc and Sinn Féin unchanged with the same percentage of the vote.

Fine Gael dropped three points to 24pc, while its Labour Party coalition partner is up two points to 8pc.

Speaking after Fianna Fáil's annual Wolfe Tone commemoration in Kildare, Mr Martin rejected the suggestion that his party would be unable to form a government if it did not agree to enter into a coalition with either Fine Gael or Sinn Féin.

"We did well in the local elections and are fighting this campaign on our own merits, putting forward policies and issues which we think are important and central to the future of the country," he said.

"We must debate the issues and then people will decide who they are going to elect and in what numbers."

However, a Fianna Fáil spokesman later confirmed that Mr Martin was open to coalition with all other parties.

This would include the newly formed Socialist Party/Anti-Austerity Alliance/People Before Profit grouping, which is up two points to 7pc, and Shane Ross's and Michael Fitzmaurice's Independent Alliance, which is up a point to 5pc.

Lucinda Creighton's Renua Ireland is unchanged at 2pc, while the Social Democrats are at 1pc.

Independents were at 12pc in the Behaviour & Attitudes poll for the 'Sunday Times'.

However, the Irish Independent understands that some Fianna Fáil members are sceptical of Mr Martin's claim that he will lead his party into government without doing a deal with either Fine Gael or Sinn Féin.

"We have to go in with someone and it's going to be an issue during the election campaign, so we may as well address it now," a senior FF TD said.

The source said it was more likely that Fianna Fáil would form a coalition with Fine Gael, as Sinn Féin has ruled out forming a government with FF.

"Reality has bypassed those who think we can't form a government with Fine Gael," the source said.